Hypothalamopituitary Axis (Hpa) By Magnetic-Resonance-Imaging (Mri) In Growth-Hormone Deficiency

Structural abnormalities of the HPA have been detected by MRI in GH deficient patients. We studied 29 children(18 boys and 11 girls) between 5-21 yr of age with GH deficiency: isolated(IGHD) or associated with multiple pituitary deficiencies (MPD). 10 cases refered abnormal deliveries. All children had GH peak levels less than 4.5ng/ml during clonidine and insulin tests, and submitted to combined TRH 200ug, GnRH 100ug and insulin 0.1 U/kg tests. Absence of TSH and PRL increment after test defined the GH deficiency as pituitary, and elevated basal TSH levels and/or high peak TSH and prolonged response defined GH deficiency as hypothalamic. MRI was performed using a 1.5 Tesla (Sigma GE) system, using spin echo sequences. The anomalies observed were:total transection of the stalk (TTS), thin stalk (TS), reduced pituitary parenchyma (RPP) and ectopic neurohypophysis (ENH).